1. Field of the Invention
The invention relates to a method for charging and discharging short-cycle and/or coating presses with layered pressing material which comprise carrier plates with top-side and bottom-side enhancement layers made from thermosetting synthetic resin or thermosetting synthetic resin films, in which a transport device, moveable between the coating, press, and depositing tables is provided with clamping and suction devices. The clamping devices grip the pressing material on both longitudinal sides and move into the pressing chamber, deposit the pressing material, and move out of the pressing chamber. After the subsequent pressing operation, the press will then be opened, and the finished plate is sucked up by the inserted suction devices, lifted, and moved out of the pressing chamber. The invention also relates to a device for carrying out the method according to the invention.
2. Related Prior Art
A similar method, and its accompanying system, is disclosed in DE 19 11 764 A1 and DE 23 63 795 A1. According to the aforementioned method and system, to execute transverse movements to charge the press and deposit the pressing material, the pressing material is gripped on the outer edge by clamping elements and inserted into the pressing chamber. To insert the discharging device into the short-cycle and/or coating press, however, various kinematic, moveable elements are utilized for accepting the finally pressed plate. As a result, separate control functions must be used and the resultant mechanical design has a relatively large number of different functional parts, and thus is not only complicated, but is also demanding to maintain.
Different widths B1 and B2 are compensated for by varying the approach of the clamping and support elements, but with the disadvantage that, in the case of thin wide pressing material, the inherent weight of the pressing material causes so large a sag that the lower surface or the film of the pressing material rubs on the pressing plate of the lower pressing/heating plate and the product is damaged. The problem is partially solved by setting a larger distance to the pressing/heating plate, which results in a disadvantage when depositing the pressing material because of increased dropping (depositing) heights and the risk associated therewith, of displacing the pressing material or films on the carrier plate. Practically, to overcome this problem the point of attack of the upper clamping roller, with respect to the support elements, is displaced so far outward that the pressing material is deformed in accordance with the bending line in order to prevent rubbing of the pressing material. The risk of clamping marks disadvantageously exerts an influence in the case of this clamping, particularly given thin pressing material with sensitive films. This means that the surface quality of the product is impaired.
The problem of the sag in the case of thin and wide pressing packages was solved by DE 39 14 866 A1, which utilizes support strips inserted in a transverse fashion below the pressing material in accordance with the insertion path, depending on the width B1 or B2 and the sagging response and are inserted into the press by means of the support and transport belts arranged on the support strips. The relatively large depositing height necessitated by the design of the support belts is disadvantageous. Furthermore, extremely high positive and negative accelerations for shortening the mechanical charging times are not possible because the package of pressing material is displaced by the forces acting when the static friction is exceeded.
Charging and discharging devices of short-cycle presses according to DE 28 47 273 A1 and DE 32 46 720 A1 operate by driving the gripper clamping strips and the sucker strip tools with the same parallelogram linkage system. The guiding arms, which can mostly be swiveled out pneumatically, pursue a sinusoidal movement, as a result of which the acceleration cycles and braking operations by means of damping elements, in part additional, in the end positions of the pressing material tray and/or pressing material holder can no longer be exactly repeated. This applies, in particular, in the case of different format widths with effects on the path lengths and the operating speeds, particularly, in the case of transverse movements in the required millisecond range. It is a further disadvantage in these swiveling arm systems that the compensation of relatively large differences in format width entails relatively large lever lengths, and thus relatively large flywheel forces.
According to a further patent DE 35 03 156 A1, the transverse insertion of the support strips with a different sagging response of the pressing material, principally, in a similarly advantageous way as according to DE 39 14 866 A1, with the difference that the package of pressing material is inserted into the press on this support strip, it being the case that during the insertion (charging) movement the package of pressing material remains fixed on the support surface of the support strips by means of vacuum suction nozzles, with the disadvantage that for the purpose of shortening the mechanical charging times in the case of high accelerating and braking forces only the lower film remains fixed, and the clamping plate situated above can be displaced with the upper film, which becomes even more critical in the case of a double film covering. This renders it impossible for the pressing material to be inserted quickly into the pressing chamber without detaching or displacing the upper film.
It is an object of the invention to allow for the insertion of a package of pressing material, given a different sagging response of the package of pressing material, into the short-cycle and/or coating press even in the case of extremely high accelerating or decelerating forces.
It is another object of the invention to reduce the mechanical charging times without displacing the package of pressing material.
It is yet another object of the invention to be able to reliably deposit the pressing material onto the lower pressing plate without displacing the film.
It is a further object of the invention to reduce the mechanical charging and discharging times, that is, reduce the time of the production cycle as a whole.
Accordingly, the invention consists of a method for charging and discharging short-cycle and/or coating presses with layered pressing material in a pressing chamber which is located between a charging region and a discharging region and in which the pressing material is pressed into a plate, the method comprising:
a) opening the pressing chamber;
b) inserting a first transport device having a plurality of clamping devices into the charging region wherein the first transport device is inserted linearly in a direction transverse to a longitudinal central axis from a pair of supply axes to a pair of charging and discharging axes, wherein each supply axis is located on an opposite side of the longitudinal central axis, wherein each charging and discharging axis is located on an opposite side of the longitudinal central axis between the longitudinal central axis and its respective supply axis, and wherein each charging and discharging axis is located further from the longitudinal central axis than from its respective supply axis;
c) inserting a second transport device having a plurality of suction devices into the pressing chamber, wherein the second transport device is inserted linearly in a direction transverse to the longitudinal central axis from the pair of supply axes to the pair of charging and discharging axes;
d) clamping the pressing material in the charging region
e) depositing pressing material in the pressing chamber;
f) moving the first transport device into the pressing chamber while jointly moving the second transport device into the discharging region, wherein the first and second transport
g) depositing the pressing material onto a lower heating element in the pressing chamber removing
h) depositing the pressed plate in the discharging region;
i) withdrawing the first transport device from the pressing chamber and the second transport device from the discharging region, wherein the first and second transport devices are withdrawn in a linear direction transverse to the longitudinal central axis from the pair of charging and discharging axes to the pair of supply axes; and
j) returning the first transport device to a first original position for a new cycle; and
n) returning the second transport to a second original position for a new cycle.
An additional method for charging and discharging short-cycle and/or coating presses with layered pressing in a pressing chamber which is located between a charging region and a discharging region and in which the pressing material is pressed into a plate, the method comprising:
a) inserting a first transport device having a plurality of clamping devices into the charging region, wherein the first transport device is inserted linearly in a direction transverse to a longitudinal central axis from a pair of supply axes to a pair of charging and discharging axes, wherein each supply axis is located on an opposite side of the longitudinal central axis, wherein each charging and discharging axis is located on an opposite side of the longitudinal central axis between the longitudinal central axis and its respective supply axis, and wherein and each charging and discharging axis is located further from the longitudinal central axis than from its respective supply axis;
b) inserting a second transport device having a plurality of suction devices into the pressing chamber, wherein the second transport device is inserted linearly in a direction transverse to the longitudinal central axis from the pair of supply axes to the pair of charging and discharging axes;
c) clamping the pressing material to the first transport device;
d) opening the pressing chamber;
e) suctioning the plate in the pressing chamber to the second transport device;
f) moving the first transport device into the pressing chamber and the second transport device into the discharging region;
g) depositing the pressing material onto a lower heating element in the pressing chamber;
h) removing the first transport device from the pressing chamber, wherein the first transport device is withdrawn in a linear direction transverse to the longitudinal central axis from the pair of charging and discharging axes to the pair of supply axes;
i) depositing the pressed plate in the discharging region;
j) withdrawing the second transport device from the discharging region, wherein the second transport device is withdrawn in a linear direction transverse to the longitudinal central axis from the pair of charging and discharging axes to the pair of supply axes;
k) returning the first transport device to a first original position; and
l) returning the second transport device to a second original position.
There is also provided a device for charging and discharging short-cycle presses, comprising a charging truck comprising at least two support spars, wherein the charging truck is movable and is guided by the support spars on a pair of guide rails; a plurality of clamping devices fastened to the support spars; a discharging truck comprising at least two support spars, wherein the discharging truck is movable and is guided by the support spars on the pair of guide rails; and a plurality of suction devices fastened to the support spars of the discharging truck.